HIGH EFFICIENT DYE-SENSITIZED SOLAR CELLS USING TiO2-MULTIWALLED CARBON NANO TUBE (MWCNT) NANOCOMPOSITE

Abstract

The invention provides high efficient dye-sensitized solar cells using tio 2 -carbon nano tube (MWCNT) nanocomposite. More particularly, the invention provides TiO 2 -MWCNT nanocomposites prepared by hydrothermal route which result in higher efficiency of the dye sensitized solar cell.

1 . A hydrothermal process for the preparation of Titanium dioxide-Multi-walled carbon nanotubes (TiO 2 -MWCNT) nanocomposite, and the said process comprising the steps of:
 vi. hydrolyzing Titanium compound precursor in water;   vii. sonicating hydrolysed presoursor of step (a) with MWCNTs;   viii. transferring product of step (b) to autoclave vessel with H 2 SO 4  and kept at 150-200° C. for 12-24 hours;   ix. washing product of step (c) with water; and   x. drying the product of step (d) at about 50-60° C. in dust proof environment to obtain TiO 2 -CNT nanocomposite.   
     
     
         2 . A hydrothermal process as claimed in  claim 1 , wherein said titanium precursor/compound is hydrolysable at room temperature, preferably 20-30° C., preferably titanium isopropoxide or titanuim chloride. 
     
     
         3 . Titanium dioxide-Multi-walled carbon nanotubes (TiO 2 -MWCNT) nanocomposite as prepared by the process as claimed in  claim 1 , wherein the wt % of CNT with respect to TiO 2  in the nanocomposite used is in the range of 0.01-0.5 wt %. Titanium dioxide-Multi-walled carbon nanotubes (TiO 2 -MWCNT) nanocomposite as prepared by the process as claimed in  claim 1 , wherein the thickness of said nanocomposite film is 1-15 microns. 
     
     
         4 . A process for the preparation of a solar cell using Titanium dioxide-Multi-walled carbon nanotubes (TiO 2 -MWCNT) nanocomposite as claimed in  claims 1  to  4 , wherein the said process comprising the steps of:
 I. putting 200 microlitre drops of the TiO 2 -CNT nanocomposite as obtained in step (v) of  claim 1  on Flourine doped tin oxide conductive and hydrolyzed glass substrate; 
 II. controlling the thickness of the film with 0.5 micron-thick scotch tape; forming film by doctor-blading process; 
 III. heat treating the film as obtained in step (h) at a temperature of 450° C. for 1 h. 
 IV. sensitizing TiO 2 -CNT nanocomposite film as obtained in step (i) with standard ruthenium-based N3-dye to obtain dye sensitized TiO 2 -CNT nanocomposite film; 
 V. preparing electrode by using dye sensitized TiO 2 -CNT nanocomposite film as obtained in step (j); 
 VI. prepareing dye sensitized TiO 2 -CNT nanocomposite solar cell by using electrode as obtained in step (k), counter electrode and liquid electrolyte. 
 
     
     
         6 . A process as claimed in step (VII) of claim  5 , wherein counter electrode used is platinum-coated FTO (Pt—FTO) substrate. 
     
     
         7 . A hydrothermal process as claimed in claim  5 , wherein liquid electrolyte consisting of 0.1 M lithium iodide, 0.05M iodine in acetonitrile. 
     
     
         8 . A process as claimed in claim  5 , wherein the improved efficiency of solar cell ranging between 5-15%. 
     
     
         9 . Use of process as claimed in any of the preceding claims for improving efficiency of solar cell is greater than 5%.